Celebrating 58 Years in the Camera Repair Business

Digital camera repair: Nikon Coolpix, Fuji FinePix
Film camera repair: 35mm, SLR, large format, movie cameras
 

Camera Club Newsletters

The Lens Hood

by Gerald L. Sanford, MNEC 

A few weeks ago, I stopped to watch several photographers trying to arrange a good angle of some egrets along the banks of a river.  The sun was very bright and there were "scattered" light rays everywhere, but no one was using a lens shade!  So, dear friends, let us take a little "trip" through your lens to see what a DEEP lens hood can do for you. 

Think of your lens as a "living thing"!  It fairly "pulsates" with chunks of light that you expect it to swallow, digest, and then produce a prize-winning photo!  But will it?  That depends upon several factors.  That large glass at the very front of the lens is a collector of light!  From everywhere!  Even light you did not see!  This collector lens element then starts the millions of pinpoints of light on their journey through two to three or more elements where they are tortured and bent in preparation for the "big squeeze" through the diaphragm hole (or iris).  Many of the pinpoints on the outer edge do not make it, and "die a slow death" bouncing back and forth between iris and glass and absorbed by the lens coating.  Remember, these tiny pinpoints are carrying a very small part of your photo, whether they be unwanted stray light or part of the beautiful picture!  Now, the light points that survived the iris "big squeeze" are turned upside down and moved left-to-right and right-to-left, then shoved through two to four more glass elements for more correction work, then finally gather together, as a family, to form an image on the film.  A prize winner?  Probably not, too much stray light from the lack of a DEEP lens shade, caused the photo to look dull and uninteresting.  No impact!! 

Long ago, I realized that the average commercial shade was too shallow, so I added to it a band of one quarter inch thick, dark gray foam rubber, one and a half to two inches wide, using a "touch" of rubber cement.  Many of my Nikon lenses have a 52 mm filter thread to which I added a 52 mm to 67 mm step up ring and a 67 mm Tiffen lens shade.  I glued a one and a half inch band of gray foam to the 67 mm shade, that made a useful two and three quarter inch hood that will not darken corners on a 50 mm, and on up into telephoto focal lengths.  The key to it all is the step up ring, which must become larger in diameter, along with matching shade, to reduce or eliminate darker corners from wide angle lenses.  Point your camera to a bright sky and watch the corners in the viewfinder while sliding the foam strip forward and backward to obtain the best position to eliminate vignetting of the corners.   The dark gray foam absorbs much stray light, and is also soft and easy to carry in a camera bag.  Most all foam supply shops have quarter inch foam in stock.  I purchased my foam from Bonnie Foam on Western Avenue in Allston, MA. Also, darkened corners (vignetting) are more easily seen in the viewfinder if you stop down to f11-16 while observing, assuming your camera has a preview button/lever. 

The winter season brings it's own particular reflected light problems from snow and ice and a slanting low sun, so a DEEP lens hood is very helpful.   Wide-angle lenses, 24-28-35mm will require a 72 mm shade to start, then lengthen it with foam to suit your particular lens.  It will be big!!  Please note that Hollywood photographers use large bellows-type hoods to reduce reflected glare.  A filter makes a terrific stray light catcher with the tiny points of light bouncing back and forth like Ping-Pong balls!  Here, again a DEEP hood will work to reduce the incoherent "junk light". 

 

 

Sanford Camera Repair
1056 Massachusetts Avenue
Arlington, MA 02476
781 648 2505